| (19) |
 |
|
(11) |
EP 0 387 994 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
08.01.1992 Bulletin 1992/02 |
| (43) |
Date of publication A2: |
|
19.09.1990 Bulletin 1990/38 |
| (22) |
Date of filing: 07.02.1990 |
|
|
| (84) |
Designated Contracting States: |
|
BE DE FR IT |
| (30) |
Priority: |
15.03.1989 GB 8905972
|
| (71) |
Applicant: GEC ALSTHOM (M & I) LIMITED |
|
Manchester M17 1PR (GB) |
|
| (72) |
Inventor: |
|
- Worthington, Hugh Malcolm
Northwich,
Cheshire (GB)
|
| (74) |
Representative: Kirby, Harold Victor Albert (GB) |
|
The General Electric Company plc
GEC Patent Department
Waterhouse Lane
GB-Chelmsford, Essex CM1 2QX
GB-Chelmsford, Essex CM1 2QX (GB) |
|
| |
|
| (54) |
High temperature transformers |
(57) A transformer whose windings are insulated with cellulose-based materials and are
immersed in a carboxylic ester liquid, the liquid and the load capacity rating of
the transformer being such that the normal winding hot-spot temperature is in the
range 110°C to 130°C, preferably in the region of 130°C, and thus substatially hotter
than 98°C.